Internet conglomerate IAC posted a $1 billion loss in the fourth quarter after writing down the value of its search division, which includes Ask, Citysearch and Dictionary.com, by $992 million.

The result is that Ask is now worth far less than the $1.7 billion IAC CEO Barry Diller shelled out for it in 2005, when the site, known then as Ask Jeeves, still seemed like a serious rival to Google.

Despite a shorter name and splashy ad campaign, Ask is now the fourth-ranked search engine, with just 4 percent of the market. Last year, Diller all but hung a for-sale sign on Ask when he said the search industry was ripe for consolidation. After kicking off the sale speculation, however, Diller said yesterday that Ask wasn’t on the auction block.